1) Field of the Invention
The present invention relates to pill packaging and, more particularly, to apparatuses and methods for delivering and packaging pills, tablets, capsules, and the like.
2) Description of Related Art
Pharmaceutical products such as pills, tablets, capsules, caplets, gel caps, dragees, and the like are often packaged in containers such as bottles, pouches, blister packages, sachets, or boxes. Each container may comprise a plurality of pill receptacles that are to be individually filled with one or more pills. This procedure is preferably performed by an automated machine capable of precisely and accurately delivering the pills at a high rate of speed. Conventional packaging machines include a plurality of dispensing tubes and chutes that guide the pills toward the pill receptacles. Precise orientation and placement of the pills can be critical to the process, for example when the pills are placed into a disposable pouch that is subsequently covered with foil. An exemplary form of such an apparatus is described in U.S. Pat. No. 5,737,902 to Aylward for “Apparatus and Method for Packaging Pills.” One embodiment of the packaging apparatus includes a tray for supporting an accumulation of pills over a drop chute. The tray is reciprocally raised and lowered to cause the pills to fall through an opening in the tray and into a tube that extends through the opening of the tray. The pills fall through the tube and into the drop chute, which guides the pills toward a container.
Although this type of feeder has achieved commercial acceptance, problems may arise if the tube or drop chute becomes blocked with pills. Blockage of the tube or drop chute can occur if adjacent pills shingle upon one another. Shingling occurs when a pill becomes wedged between an adjacent pill and the wall of the tube or chute. For example, as shown in FIG. 12, shingling can occur in a dispensing tube T where the pills P are stopped by pins N1, N2 that control the rate of release of the pills. The shingling of the pills P prevents the pills from falling though the tube T when the pins N1, N2 are retracted from the tube. Blockage within the tubes can increase maintenance costs, reduce the speed of the packaging process, and cause some pill receptacles to go unfilled. Unfilled pill receptacles result in defective packages and necessitates rework, thereby increasing packaging costs.
In order to reduce the likelihood of shingling, some tubes are designed to be only slightly larger than the pills that fall therethrough so that there is insufficient space between a pill and the wall of the tube for another pill to fit. However, the size of the pills is determined in part by the composition of the pill material, and therefore pill sizes may vary from lot to lot. Thus, keeping the tube size closely matched to the pill size can necessitate different sized tubes for different lots, even if successive lots contain similar pills. The need for additional tubes increases the average expense of operating the machine. Additionally, changing the tubes between each lot requires stopping the machine and, hence, decreases the throughput. Moreover, shingling can still occur even when tubes are changed for each lot, especially if there are variations in pill size within a single lot of pills. The particular characteristics of some pills, such as shape, hardness, surface roughness, and the like, can also increase the likelihood of shingling.
Another problem occurs when the pills that are disposed on the tray do not fall into the tube. Although the reciprocal raising and lowering of the tray is usually effective in agitating the pills, the pills sometimes become arranged such that they are not easily moved and encouraged into the tube. One such arrangement occurs when two or more pills become simultaneously lodged in the opening of the tube. Until this arrangement is disturbed, the lodged pills block each other and the other pills from entering the tube. Alternatively, a number of pills may become arranged in a “bridged” configuration, wherein the pills are stacked in a relatively stable structure that defines a hollow, cave-like interior. This stacked arrangement also prevents pills from entering the tube. Like blockage within the tubes, failure of the pills to fall into the tubes can reduce the speed of the packaging process and cause some pill receptacles to go unfilled. Again, defective packages, rework, and increased maintenance increases packaging costs.
Thus, there is a need for an improved packaging apparatus for delivering and placing pills and the like into pill receptacles and containers. Such an apparatus should not have the disadvantages associated with conventional systems and should be able to precisely and reliably place pills into pill receptacles in a desired orientation. Such an apparatus should decrease the risk of blockage of pills within the tube, for example, by shingling, and should also increase the likelihood and efficiency of delivering pills into the tube.